The NUT in the N=2 Superalgebra

We study how the supersymmetry algebra extension of N=2 supergravity with central charges describes the NUT charge in a duality-covariant way. The stationary BPS states of N=2 supergravity can be embedded in the flat space solution of the timelike reduced theory. Upon reduction, the Killing superalgebra extension and the global superalgebra of charges are described covariantly under the coset structure of the three-dimensional theory. The integral of the Nester-Witten form given by Gibbons and Hull for N=2 has a covariant generalization that includes the NUT charge.Comment: 28 pages, v3: final versio

The NUT in the N=2 Superalgebra

We study how the supersymmetry algebra extension of N=2 supergravity with central charges describes the NUT charge in a duality-covariant way. The stationary BPS states of N=2 supergravity can be embedded in the flat space solution of the timelike reduced theory. Upon reduction, the Killing superalgebra extension and the global superalgebra of charges are described covariantly under the coset structure of the three-dimensional theory. The integral of the Nester-Witten form given by Gibbons and Hull for N=2 has a covariant generalization that includes the NUT charge.Comment: 28 pages, v3: final versio

From accelerating and Poincar\'e coordinates to black holes in spacelike warped AdS3_3, and back

We first review spacelike stretched warped AdS$_3$ and we describe its black hole quotients by using accelerating and Poincar\'e coordinates. We then describe the maximal analytic extension of the black holes and present their causal diagrams. Finally, we calculate spacetime limits of the black hole phase space $(T_R,T_L)$. This is done by requiring that the identification vector $\partial_\theta$ has a finite non-zero limit. The limits we obtain are the self-dual solution in accelerating or Poincar\'e coordinates, depending respectively on whether the limiting spacetimes are non-extremal or extremal, and warped AdS with a periodic proper time identification.Comment: 43 pages, 11 figures. v4: version to appear in CQG, presentation changes (parts to appendices

Motions of sounds, bodies, and souls [Plato, Laws VII. 790e ff.]

This article explores how Plato, in his “metaphysical” dialogues, sees the specific properties of motion (and especially of motion in music), which lend themselves to adaptation for the purposes of maintaining or restoring the health of the soul. Plato explores the property of regular or rhythmic motion in particular. The attention has been drawn to the analogy between the calming effect of music, at the human level, and the Demiurge’s achievement in willing the world into existence. The focus of the article lays on the Laws, in which the principle of musical motion plays a central role in resolution of the contradictions between material and spiritual, natural and physiological, medical and educativ